Metal–Insulator–Metal (MIM) capacitors based on high-k oxides require stability with the applied electric field. However, experiment reveals a nonlinear behavior of capacitance with ac or dc bias. In this work, we measure capacitance–voltage nonlinearities for Au/10-nm HfO₂/M (where M = TiN, Pt, W, and AlCu alloys). It is observed that ac capacitance is strongly dependent on the bottom electrode material. This dependency is discussed through the correlated barrier hopping (CBH) model. Accordingly, the ac nonlinearity is ascribed to the polarization of isolated defect pairs, which in turn increase as the maximum barrier height decreases. This induces higher nonlinearity as compared to the dc one. For the dc bias, oxygen affinity of active metal electrode may describe the origin of dc nonlinearities.

基于高k氧化物的金属-绝缘体-金属（MIM）电容器需要在施加的电场下保持稳定。然而，实验揭示了具有交流或直流偏置的电容的非线性行为。在这项工作中，我们测量了Au / 10 nm HfO ₂ / M（其中M = TiN，Pt，W和AlCu合金）的电容-电压非线性。可以观察到，交流电容在很大程度上取决于底部电极材料。通过相关势垒跳跃（CBH）模型讨论了这种依赖性。因此，交流非线性是由于隔离缺陷对的极化引起的，极化随着最大势垒高度的减小而增加。与直流电相比，这会引起更高的非线性。对于直流偏置，活性金属电极的氧亲和力可以描述直流非线性的起源。